backup.sh

#!/bin/bash
# The makings of a simple backup utility. In cronjob, add:
# 45 * * * * /path/to/backup.sh

# CHANGE THIS
DAILY_BACKUP_HOUR="00" # the hour when content is dumped to permanent daily backup
function dumpValuableContent() {
  curl -O http://example.com
}

# DON'T CHANGE THIS

TMPDIR="/tmp/backup$$"
CURRENT_HOUR=`date +%H`
CURRENT_DATE=`date +%y%m%d`
BACKUPDIR=$HOME/backup

#########
# UTILS
#########
function ensureExistsAndEmpty() {
  if [ -d $1 ] ; then
    rm -rf $1
  fi
  mkdir -p $* # can also pass in subdirs
}

##############################
# GET CONTENT
##############################
mkdir $TMPDIR
if [ "$?" != "0" ] ; then exit ; fi
cd $TMPDIR
dumpValuableContent
if [ "$?" != "0" ] ; then exit ; fi

##############################
# PUT INTO PERIODIC DIRS
##############################

ensureExistsAndEmpty $BACKUPDIR/hourly
HOURDIR=$BACKUPDIR/hourly/$CURRENT_HOUR
ensureExistsAndEmpty  $HOURDIR
cp $TMPDIR/* $HOURDIR

if [ "$CURRENT_HOUR" == "$DAILY_BACKUP_HOUR" ] ; then
  DAYDIR=$BACKUPDIR/daily/$CURRENT_DATE
  ensureExistsAndEmpty $DAYDIR
  cp $TMPDIR/* $DAYDIR
fi

##############################
# CLEAN UP
##############################
rm -fr $TMPDIR